1. Field of the Invention
The present invention relates to a set top terminal used for a television receiver and the like.
2. Description of the Related Art
A conventional set top terminal will be described with reference to FIG. 11. The conventional set top terminal includes: an input terminal 1; a tuner part 2 connected to the input terminal 1; a signal processing part 3; a modulation part 4; an output terminal 5 connected to an output of the modulation part 4; a control part 6 for controlling the entire set top terminal; a display part 7; a common part 8; and a key operation part 9.
The signal processing part 3, which consists of, for example, a video detection circuit or a descrambler, is connected to an output of the tuner part 2. The modulation part 4, which consists of an RF converter and the like, is connected to an output of the signal processing part 3. The control part 6 has a micro computer and is connected to both the tuner part 2 and the signal processing part 3. The display part 7 is constituted by light emitting diodes (hereinafter, referred to as LEDs) capable of displaying two digit or four digit numbers. The common part 8 receives a signal transmitted from a remote control transmitter (not shown). Inside a body of the set top terminal, a power source part 10 is provided.
The set top terminal is such that its body is constituted by a chassis 11 and a cover made of resin (not shown) covering the upper part of the chassis 11. A main board 12 is attached inside the chassis 11. In approximately the center of one lateral side 13 of the chassis 11, the tuner part 2, to which the input terminal 1 is fixed, is provided. Furthermore, in the vicinity of one longitudinal side 14a, the output terminal 5 is fixed on the lateral side 13.
The modulation part 4 and the signal processing part 3 are mounted onto the main board 12 in the vicinity of the output terminal 5. The control part 6 is mounted onto the main board 12 in the rear of the signal processing part 3. In the vicinity of the other lateral side 14 facing the lateral side 13, the key operation part 9 and the display part 7 consisting of LEDs are placed so as to be attached onto the main board 12. The power source part 10 is provided in the vicinity of the other longitudinal side 14b.
The set top terminal is capable of receiving channels of about one hundred cable television services. Therefore, various specifications can be selected depending on the demand of a user. In the conventional configuration, however, it is necessary to prepare the main boards corresponding to the number of specifications for satisfying these various specifications. Therefore, it is necessary to control a great number of main boards.